Now, after relying on this set of night-lights for two years, I’ve come to consider them a nightly essential, and they’re paying off in their per-use cost; if I need to replace them, I won’t ...

Not long ago, one could gaze at the night sky and see the Milky Way. Light pollution, or artificial light at night, now significantly impedes our view of the Milky Way; air pollution contributes, too.

Using a measure of brightness called “magnitude per square arc-second,” the brightest, Monday-Night-Football night sky is about 16 mpsas, and the darkest sky, with zero light pollution, is 22.